Scanning tunneling luminescence (STL) can be used to investigate the optical properties of nanostructures with high spatial resolution beyond the diffraction limit of light. To get appropriate STL spectra, one needs to modify the tip repeatedly. However, such irreversible tip modification often leads to very unstable tips. Here, by using a scanning tunneling microscope (STM) tip, we demonstrate that STL spectra are tunable via silver nanocluster arrays fabricated directly on a silver surface. The silver nanoclusters are created by transferring silver atoms from the silver tip to the silver surface under STM. We found that the STL spectra were enhanced (suppressed) at higher (lower) energy on the clusters and that they showed opposite behaviors between the nanoclusters. Without relying on the irreversible tip shape modification, our findings indicate that we can tune the STL spectra simply by moving the STM tip over the nanoclusters. Our method can be used to provide a tunable light source for systematic nano-optical experiments and for nanoscale optical devices.

中文翻译：

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在银表面上具有银纳米团簇的可调谐等离子体量子光源

扫描隧道发光 (STL) 可用于研究具有超出光衍射极限的高空间分辨率的纳米结构的光学特性。为了获得合适的 STL 光谱，需要反复修改尖端。然而，这种不可逆的尖端修改通常会导致非常不稳定的尖端。在这里，通过使用扫描隧道显微镜 (STM) 尖端，我们证明了 STL 光谱可通过直接在银表面上制造的银纳米簇阵列进行调谐。银纳米团簇是通过在 STM 下将银原子从银尖端转移到银表面而产生的。我们发现 STL 光谱在簇上的较高（较低）能量下被增强（抑制），并且它们在纳米簇之间表现出相反的行为。不依赖于不可逆转的尖端形状修改，我们的研究结果表明，我们可以通过将 STM 尖端移动到纳米团簇上来简单地调整 STL 光谱。我们的方法可用于为系统纳米光学实验和纳米级光学器件提供可调光源。